1. Field of the Invention
The invention relates to a conveying system, comprising an endless conveyor mat extending between two divert wheels, for conveying products between the divert wheels in a conveying direction, which conveying system further comprises a slide-over device for transferring, adjacent a divert wheel from or towards a conveying face of the conveyor mat, products conveyed by the conveyor mat towards or from said divert wheel, which slide-over device comprises a number of separately detachable fingers extending into the conveying face, the conveying face being substantially flat and having a number of substantially straight slots extending in conveying direction, and each finger of the slide-over device cooperating with a slot.
The invention also relates to a slide-over device for transferring, adjacent a divert wheel from or towards a conveying face of a conveyor mat, products which are conveyed by that conveyor mat in a conveying direction towards or from said divert wheel, which slide-over device comprises a number of separately detachable and substantially parallel, outwardly extending fingers for cooperating with a conveying face.
2. Description of Related Art
Such conveying systems and slide-over devices are known and are used for conveying all kinds of products in a large number of different environments. A particularly exacting application of such conveying system and such slide-over device concerns the transport and transfer of products through a pasteurizer for pasteurizing the products.
During pasteurization, products, in particular beverages, after having been introduced into a package, are heated for some time so as to prolong the storage life of the products. To that end, the sealed packages containing the product are placed on a conveying track and passed through an encasing forming a long, watertight tunnel. The conveying number of zones where warm water having per zone a different temperature is sprayed onto the packages, for instance 20-40-60-80-60-40.degree. C. Such conveying track conveys the products at a speed of about 0.5-1 m/sec and has a capacity of about 30-70,000 packages per hour. In the temperature zones, about 25 m.sup.3 water per hour is sprayed onto the products per m.sup.2 track surface area. In order to use the water more efficiently, the conveying track is preferably of a double-decked design. The packages conveyed through the pasteurizer by means of the conveying track are usually pots or bottles manufactured from metal, plastic or glass.
For reasons of cost, attempts have been made to design the conveying track as an endless conveyor mat circulating in a conveying direction between a first divert wheel and a second divert wheel. Such conveyor mat is known from EP 0 339 309. The conveyor mat is built up from a large number of interconnected plastic modules, each built up from a number of fins extending in parallel, side by side relationship in conveying direction. A number of these fins are provided with a raised rib. The top sides of these ribs together constitute a conveying face. Adjacent the divert wheels, the products are transferred towards or from the conveying face by a slide-over device comprising a comb having a flat part that carries tooth-shaped projections. The teeth project between the raised ribs so that during discharging, the foremost products are transferred from the conveying face and pushed onto the flat part of the comb via the teeth by the following products, while via the second divert wheel, the modules continue their endless path. During the supply of products, the foremost products are pushed, at the location of the first divert wheel, from the flat part of the comb onto the conveying face via the teeth by following products.
A drawback of the known conveying system and of the existing slide-over device is that they are not suitable for conveying glass packages through a pasteurizer. As it is, during pasteurization, the pressure in the package increases This may lead to breakage of about 1% of the glass packages as a consequence of weak spots in the glass and/or an unduly high filling degree of the package. In the known conveyor mat and in the known conveying system, the glass fragments of the broken packages get stuck between the ribs and/or fins of the modules. Thus, the slide-over device gets damaged. In particular, the teeth of the comb break off or are bent by glass fragments stuck between the ribs and/or the fins, as a result of which they form an obstacle to the packages. Further, glass fragments may accumulate under the flat portion of the comb of the slide-over device, causing the comb to rise in the conveying plane and the teeth to form an obstacle to the products. Hence, in practice, in a pasteurizer for products packed in glass packages, such conveying systems and slide-over devices are hardly used as conveying track.
This is also the case when such plastic conveying systems and plastic slide-over devices are used in other circumstances where high requirements are imposed on the temperature resistance, wear resistance and sturdiness.
DE 20 38 966 teaches a slide-over device in the form of a finger plate whose fingers are each intended to cooperate with a longitudinal groove in the conveying face of a conveyor, such as a conveyor belt. The finger plate comprises a swivelable support beam to which the fingers are each separately detachably connected by means of a screw.
A drawback of this finger plate is that the fingers are not directly accessible for being detached, but first have to be swiveled upwards together with the support beam. In particular for applications where the fingers are poorly accessible and/or the slide-over device comprises a relatively large number of fingers, as in a slide-over device incorporated into a pasteurizer, the detachment and replacement causes problems.